Bi-Level Weighted Histogram Equalization for Scalable Brightness Preservation and Contrast Enhancement for Images

A new technique, Bi-Level Weighted Histogram Equalization (BWHE) is proposed in this paper for the purpose of better brightness preservation and contrast enhancement of any input image. This technique applies bi-level weighting procedure on Brightness preserving Bi-Histogram Equalization (BBHE) to enhance the input images. The core idea of this method is to first segment the histogram of the input image into two, based on its mean and then weighting constraints are applied to each of the sub-histogram separately. Finally, those two histograms are equalized independently and their union produces a brightness preserved and contrast enhanced output image. This technique is found to preserve the brightness and enhance the contrast of input images better than its contemporary methods.